Material rising up into the pharynx from the stomach and intestinal tract represents, particularly for the unconscious patient being ventilated, a permanent reservoir of microbes, and may provoke or exacerbate pulmonary infection from the lower pharynx on intubation. Artificially ventilated intensive care patients are looked after through secretion-stimulating gastric probes or feeding tubes whose throughput as a rule is still insufficient to put a stop to gastro-oesophogeo-pharyngeal reflux beside or along them. As a result the greater number of sedated or artificially ventilated patients are virtually overwhelmed by high-grade bacterially contaminated material in the pharyngeal, nasal and postnasal regions.
On account of various difficulties in the search for a simple mechanical oesophageal or gastric blockade tolerable in the long term this infective problem potential could not until now be satisfactorily resolved. What was tried out therapeutically, and generally tolerated, was essentially medicinal/antibiotic (e.g. selective bowel decontamination).
Since the structures of the oesophageal wall react extremely sensitively to persistent pressure or tension, the conventional blocking techniques, in which the walls of the attached structures are placed under tension (as a rule by a balloon) are not, or only with limitations, applicable in the case of the oesophagus.
The purpose of the invention is to rectify the disadvantages just mentioned and to present a stomach probe with which closing off or filling out of the oesophagus is possible without deleterious effect on its wall structures.
For the resolution of this aim the stomach probe is equipped with the characteristics of Patent claim 1.
The oesophagus is a dynamic structure constantly changing in shape. The tonus of its wall, and its lumen, are subject to considerable active and passive functional fluctuations. Tamponization of the oesophagus by a bladder like that of the invention fits in with their physiological dynamic and thus guarantees a simple self-regulating and well-tolerated closure or filling of the gullet. Regurgitation of material highly contaminated with microbes from the stomach and gut regions into the oral, nasal or pharyngeal cavities is prevented by the invention. By means of the invention gastro-oesophageal-pharyngeal reflux is prevented by a simple self-regulating and well-tolerated mechanical blockade in the oesophageal region. Drainage of stomach contents is thus guaranteed to take place through an ordinary stomach or feeding probe.
Ulcerations or necroses of the oesophageal wall structures as a result of long-term blocking are excluded by the most far-reaching pressure-passive actions of the tampon-bladder described in the invention.
Immediately adjoining structures such as the great vessels, the accompanying nerves, the trachea and main bronchi, the lungs themselves and, not least, the heart, particularly the left atrium, are, in contrast to conventional blocking, not endangered.
The inner cavity of the tampon-bladder may be filled with the medium, through a channel lying between the inner and outer lumina, from a filling device connected to the channel. Simply operated examples of such a filling device are a reservoir or equalizing vessel, particularly one situated outside the patient. A supply of the medium sufficient to fill the inner cavity of the tampon-bladder, and in addition to allow for the abovementioned functional fluctuations of the lumen and the tonus of the oesophageal wall through further outflow or intake of the medium by expansion and collapse of the tampon-bladder, is kept in the reservoir or equalizing vessel.
In this connection it could be seen as an additional advantage for the medium to be actively led into the inner cavity of the tampon-bladder or withdrawn from the inner cavity through the channel. Such active supply and withdrawal take place through a pump which is regulated preferably to compensate for any extensive pressure-passive fluctuations in the tampon-bladder.
So that a medium is used which can be supplied or withdrawn rapidly and at the same time has a thermal capacity high enough for the adjustment of the temperature measured inside the oesophagus, it can be a fluid such as for example water or equivalent. Such a medium is simple and quick to pump and easily adjustable in temperature.
Another medium which is distinguished by compressibility as well as a certain adaptability of its own to the fluctuations mentioned above is, for instance, a gaseous one. Filling apparatus, reservoir, equalizing vessel and pump may all be used with any suitable medium and are designed accordingly.
Further advantageous embodiments of the invention derive from features in the Claims below.